Although the bulk of development and launches comes from academia, several companies build CubeSats such as large-satellite-maker Boeing, and several small companies. CubeSat projects have also been the subject of Kickstarter campaigns.[2] The CubeSat format is also popular with amateur radio satellite builders.

Contents

The CubeSat specification accomplishes several high-level goals. Simplification of the satellite's infrastructure makes it possible to design and produce a workable satellite at low cost. Encapsulation of the launcher–payload interface takes away the prohibitive amount of managerial work that would previously be required for mating a piggyback satellite with its launcher. Unification among payloads and launchers enables quick exchanges of payloads and utilization of launch opportunities on short notice.

The term "CubeSat" was coined to denote nano-satellites that adhere to the standards described in the CubeSat design specification. Cal Poly published the standard in an effort led by aerospace engineering professor Jordi Puig-Suari.[3]Bob Twiggs, of the Department of Aeronautics & Astronautics at Stanford University, and currently a member of the space science faculty at Morehead State University in Kentucky, has contributed to the CubeSat community.[4] His efforts have focused on CubeSats from educational institutions.[5] The specification does not apply to other cube-like nano-satellites such as the NASA "MEPSI" nano-satellite, which is slightly larger than a CubeSat.

In 2004, with their relatively small size, 1U CubeSats could each be made and launched to LEO for an estimated $65,000–$80,000. After delays from low-cost launchers such as Interorbital Systems,[6] more recent launch prices have been $100,000[7]–$125,000,[8] plus approximately $10,000 to construct the CubeSat.[9] This price tag, far lower than most satellite launches, has made CubeSat a viable option for schools and universities around the world. Because of this, a large number of universities and some companies and government organizations around the world are developing CubeSats—between 40 and 50 universities in 2004.

The standard 10×10×10 cm basic CubeSat is often called a "one unit" or "1U" CubeSat. CubeSats are scalable along only one axis, by 1U increments. CubeSats such as a "2U" CubeSat (20×10×10 cm) and a "3U" CubeSat (30×10×10 cm) have been both built and launched. In recent years larger CubeSat platforms have been proposed, most commonly 6U (10x20x30 cm or 12x24x36 cm[10]) and 12U (20x20x30 cm or 24x24x36 cm[10]), to extend the capabilities of CubeSats beyond academic and technology validation applications and into more complex science and defense goals.

Since CubeSats are all 10x10 cm (regardless of length) they can all be launched and deployed using a common deployment system. CubeSats are typically launched and deployed from a mechanism called a Poly-PicoSatellite Orbital Deployer (P-POD), also developed and built by Cal Poly.[11] P-PODs are mounted to a launch vehicle and carry CubeSats into orbit and deploy them once the proper signal is received from the launch vehicle. P-PODs have deployed over 90% of all CubeSats launched to date (including un-successful launches), and 100% of all CubeSats launched since 2006. The P-POD Mk III has capacity for three 1U CubeSats, or other 1U, 2U, or 3U CubeSats combination up to a maximum volume of 3U.[12]

CubeSat forms a cost-effective independent means of getting a payload into orbit.[3] Most CubeSats carry one or two scientific instruments as their primary mission payload. Several companies and research institutes offer regular launch opportunities in clusters of several cubes. ISC Kosmotras and Eurokot are two companies that offer such services.[13]

The need for such a small-factor satellite became apparent in 1998 as a result of work done at Stanford University's Space System Development Laboratory. At SSDL students had been working on the OPAL (Orbiting Picosatellite Automatic Launcher) microsatellite since 1995. OPAL's mission to deploy daughter-ship "picosatellites" had resulted in the development of a launcher system that was "hopelessly complicated" and could only be made to work "most of the time". With the project's delays mounting, Twiggs sought out DARPA funding that resulted in the redesign of the launching mechanism into a simple pusher plate concept with the satellites held in place by a spring-loaded door.[14]:151–157

Desiring to shorten the development cycle experienced on OPAL and inspired by the picosatellites OPAL carried, Twiggs set out to find "how much could you reduce the size and still have a practical satellite". The picosatellites on OPAL were 10.1 x 7.6 x 2.5 cm, a size that was not conducive to covering all sides of the spacecraft with solar cells – a requirement for a tumbling satellite. Inspired by a 4 in. cubic plastic box used to display Beanie Babies in stores, Twiggs first settled on the larger 10-centimeter cube as a guideline for the new (yet-to-be-named) CubeSat concept. A model of a launcher was developed for the new satellite using the same pusher plate concept that had been used in the modified OPAL launcher. Twiggs presented the idea to Puig-Suari in the summer of 1999 and then at the Japan-U.S. Science,Technology, and Space Applications Program (JUSTSAP) conference in November 1999.[14]:157–159

On 26 July 2006, 14 CubeSats from 11 universities and a private company were launched aboard a Dnepr rocket, the largest planned deployment of CubeSats to date.[5] The rocket failed and was destroyed during launch, obliterating the CubeSats and four other satellites aboard.[19] The launch was lost after the first stage engine shut down prematurely.[20] All satellite parts are believed destroyed. The committee investigating the failed launch concluded that the failure was caused by a malfunctioning hydraulic drive unit on the rocket's first stage.[21] The malfunction brought about control disturbances which led to roll instability and excessive excursions of yaw and pitch angles. Thrust termination occurred at 74 seconds after lift off. The launch had been postponed numerous times because the primary payload, EgyptSat 1, was not ready. Due to ITAR concerns,[citation needed] the CubeSats were moved to a different launch site, with the primary payload being BelKA, which was to be the first satellite from Belarus. The launch carried Rincon 1 and SACRED, both from the University of Arizona and UniSat-4 from the University of Rome (GAUSS team). Other projects came from the Norwegian University of Science and Technology, Hankuk Aviation University, Seoul, Korea and Polytechnic University of Turin, Italy. The Aerospace Corporation, from the United States, also had its own commercial project on board.

CubeSats launched from the International Space Station on 4 October 2012

On 3 August 2008, a SpaceX Falcon 1 launched from the Kwajalein Atoll launch facility (US) with two NASA CubeSats. They were the PREsat from NASA's Ames Research Center, and the NanoSail-D from both NASA's Marshall Space Flight Center and Ames Research Center.[26] These CubeSats were lost due to a launch vehicle failure when the rocket's first stage inadvertently made contact with the second stage after separation. The ground spare for NanoSail, the NanoSail-D2 CubeSat, was successfully launched in November 2010 and deployed from the FASTSAT satellite on a Minotaur IV launch.

On March 4, 2011, the Glory mission was lost when the fairing of the Taurus XL failed to separate from the launch vehicle. The rocket also carried three CubeSat satellites. These university satellites include the Space Science and Engineering Laboratory's Explorer-1 PRIME (E1P) developed by students at Montana State University, Kentucky Space's KySat-1 which was developed by multiple Kentucky universities plus several organizations and companies,[27] and the University of Colorado-Boulder's HERMES. This was the first of NASA's Educational Launch of Nanosatellite, or ELaNa, missions.

On February 13, 2012, three PPODs containing seven CubeSats were placed into orbit along with the Lares satellite aboard an AvioVega rocket launched from French Guyana. The CubeSats launched were e-st@r (Politecnico di Torino, Italy), Goliat (University of Bucarest, Romania), Masat-1 (Budapest University of Technology and Economics, Hungary), PW-Sat (Warsaw University of Technology, Poland), Robusta (University of Montpellier 2, France), UniCubeSat-GG (University of Rome La Sapienza, Italy), and XaTcobeo (University of Vigo and INTA, Spain).[29]

On September 13, 2012, eleven CubeSats were launched from eight P-Pods, as part of the "OutSat" secondary payload aboard a United Launch AllianceAtlas V rocket launched from Vandenberg Air Force Base, California.[30] This is the largest number of CubeSats (and largest volume of 24U) successfully placed to orbit on a single launch, this was made possible by use of the new NPS CubeSat Launcher system (NPSCuL) developed at the Naval Postgraduate School (NPS). The following CubeSats were placed on orbit: SMDC-ONE 2.2 (Baker), SMDC-ONE 2.1 (Able), AeroCube 4.0(x3), Aeneas, CSSWE, CP5, CXBN, CINEMA, and Re (STARE).[31]

Long CubeSats being launched from the ISS on February 25, 2014. The launcher is visible as well, attached to a robotic arm.

On May 7, 2013, the ESTCube-1 CubeSat, the first Estonian satellite, was placed into orbit along with the Proba-V and VNREDSat 1A satellites aboard an AvioVega rocket launched from French Guyana.

On December 5, 2013, twelve CubeSats as part of the "GemSat" secondary payload aboard a United Launch AllianceAtlas V rocket launched from Vandenberg Air Force Base, California.[39] This is the second flight of NPSCuL, so the total volume was again 24U from eight Cal Poly P-PODs. The following CubeSats were placed on orbit: AeroCube 5 (Aerospace Corp.), ALICE (Air Force Institute of Technology), SNaP, TacSat 6 & two SMDC-ONE (U.S. Army Space and Missile Defense Command), CUNYSAT 1 (Medgar Evers College), IPEX (NASA's Jet Propulsion Labaratory at Cal Poly), MCubed 2 (University of Michigan), FIREBIRD 1A & 1B (Montana State University).

A total of thirty-three CubeSats are to be deployed from the International Space Station, a feat which started on February 11, 2014. Of those thirty-three, twenty-eight are part of the Flock 1 constellation of Earth-imaging CubeSats designed by Planet Labs. Of the other five CubeSats being launched from the ISS, two are also from US-based companies, two are from Lithuania, and one is from Peru.[40]

A number of CubeSats were lost during the explosion of the Cygnus CRS Orb-3 launch vehicle.

An example of one of the ELaNa satellites is the University of New Mexico's Space Plug-and-play Architecture (SPA) proof of concept flight for the Trailblazer mission. Trailblazer is a 1U CubeSat to be launched in 2012 under the ELaNa four mission.[41]

The goal of the QB50 project is to use an international network of 50 CubeSats for multi-point, in-situ measurements in the lower thermosphere (90–350 km) and re-entry research. QB50 is an initiative of the Von Karman Institute and is funded by the European Union. Double-unit ("2-U") CubeSats (10x10x20 cm) are foreseen, with one unit (the 'functional' unit) providing the usual satellite functions and the other unit (the 'science' unit) accommodating a set of standardised sensors for lower thermosphere and re-entry research. 35 CubeSats are envisaged to be provided by universities in 19 European countries, 10 by universities in the US, 2 by universities in Canada and 3 by Japanese universities. 10 double or triple CubeSats are foreseen to serve for in-orbit technology demonstration of new space technologies. All 50 CubeSats will be launched together on a single launch vehicle. The launch is planned for mid-2015.[42] The Request for Proposals (RFP) for the QB50 CubeSat was released on February 15, 2012.

^ abThe official standard only defines up to 3U and "3U+" (a slightly larger but same-mass 3U). Larger sizes use have varying definitions depending on source. There is even confusion about 3U and 1U: the official standard claims a 3U masses at most 4 kg, while Spaceflight Services claims (see http://spaceflightservices.com/pricing-plans/ ) that 3U extends to 5 kg.

^"Cubist Movement". Space News. 2012-08-13. p. 30. When professors Jordi Puig-Suari of California Polytechnic State University and Bob Twiggs of Stanford University invented the CubeSat, they never imagined that the tiny satellites would be adopted by universities, companies and government agencies around the world. They simply wanted to design a spacecraft with capabilities similar to Sputnik that graduate student could design, build, test and operate. For size, the professors settled on a 10-centimeter cube because it was large enough to accommodate a basic communications payload, solar panels and a battery.